Israeli Prime Minister Ariel Sharon has ordered the military to step up operations against Palestinian militants.

Mr. Sharon's directive ordered the military to step up its operations, without restrictions, in order to prevent Palestinian militant attacks.

The order is directed mainly at the Gaza Strip where militants have intensified their attacks against Israeli targets in recent weeks. Late Thursday, they launched a well coordinated assault on a major commercial crossing point between Gaza and Israel proper, killing six Israelis.

Israel sealed off the Gaza Strip on Friday and cut off all contact with the Palestinian Authority.

On Saturday and Sunday militants fired mortars and rockets into Israeli settlements in Gaza and into the Israeli town of Sderot.

The violence escalated as newly elected Palestinian President Mahmoud Abbas was sworn in. Israeli Prime Minister Ariel Sharon insists there will be no contact until Mr. Abbas cracks down on the militants.

"Israel will not return to a situation where it is negotiating while its civilians are being killed. That is untenable," say Mr. Sharon's senior advisor, Dori Gold, who spoke with VOA.

Mr. Abbas has said he is pursuing negotiations with the militants, but will not use force to rein them in.

Chief Palestinian negotiator Saeb Erakat says the Israeli action unfairly targets Mr. Abbas before he has an opportunity to try to address the situation.

"They decided to suspend talks with him, what kind of logic is this? The man did not even resume [sic] his office yet; don't you give him a chance?," he said.

Mr. Abbas is expected to visit Gaza this week to push for an immediate ceasefire with the militants.

Meanwhile, Mr. Abbas also faces a wave of political challenges stemming from last Sunday's election. Forty-six election officials have resigned their posts to protest alleged irregularities in the voting.

The officials say they were forced, some at gunpoint, to keep the polls open an extra two hours, giving Mr. Abbass supporters more time to vote. International monitors say the last-minute changes increased voter turnout, but did not undermine the elections legitimacy.